Two Egyptian police officers have died while attempting to diffuse bombs in the capital Cairo.
Several other officers were injured, including head of the bomb-disposal department, General Alaa Abdel Zaher.
The authorities were alerted to the devices when militant group Ajnad Misr tweeted their location at a busy crossroads outside the presidential palace. In a change of heart, the underground opposition group said they would not trigger them but were unable to diffuse the explosives.
Monday marked the first anniversary of mass protests against former president Mohammed Mursi that brought about his downfall by the army on July 3.
Since Mursi’s removal radical Islamists have repeatedly attacked police and soldiers.
Last week the Egyptian capital’s underground railway was hit with four small homemade bombs, the first attack of its kind since the swearing -in of President Abdel Fatah al-Sissi.